Air heater and circulator for can end drying machines



Dec 18, 1945. P. E.IPEARSON AIR' HEATER AND CIRCULATOR FOR CAN END DRYING MACHINES 4 Sheecs-Sheet 1 Filed April '20, 1942 Dec. 18, 1945. P. E. PEARSON AIR HEATER AND 'CIRCULATOR FOR CAN END DRYING MACHINES 4 Sheets-Sheet 2 Filed p il 20, 1942 13, P. E. PEARSON 3 2,391,339 'AIR HEATER AND 'CIRCULATOR FOR-CAN END DRYING MACHINES 7 Filed April 20, .1942 4 Sheets-She et :5

1945- P. E. PEARSON 2,391,339

AIR HEATER AND CIRcuLAToR FOR CAN END DRYING MACHINES I Filed April 20," 1942 4 Sheets-Sheet 4 Patented Dec. 18, 1945 nental Can Company, Inc.,

corporation of New York New York, N. Y., a

Application. April 20, 1942, Serial No. 439,754

8 Claims. (C1

The invention relates generally to drying apparatus and primarily seeks to provide novel air heating and circulating means for use in machine structures adapted for drying or baking protective coatings ,or sealing compounds on can end or cone top units.

In drying machines of the character stated, there are included sets or pairs of elevator screws between which the can end or cone top units are fed and which are rotated in a manner for ele-- vating the units in spaced relation within a casing in which drying air is passed between the ture in which the rotor is mounted and indexed,

and novel means for circulating air through said casing, and also for heating the air to a greater or lesser degree in cases where it is desired to heat dry or bake the coatings on the can end or cone top units.

Another object of the invention is to provide a novel casing and air circulating structure of the character stated including a perforated sleeve which is mounted within .the circularly arranged sets of elevator screws in a manner for ,uniformly discharging or dispersing the air through the spaced units as they are being elevated.

Another object of the invention is to provide in an apparatus of the character stated, novel means for regulating the flow of the air so that a greater or lesser amount of the air is exhausted from the air circulation and a greater or lesser amount of fresh air is introduced into the air circulation so as to control the temperature in different parts of the casing and avoid fouling thereof.

Another object of the invention is to provide in an apparatus of the character stated, means for regulating the heating and distribution of the air so as to provide an upper casing chamber portion of relatively high temperature, and a lower casing.

chamber portion of relatively low temperature wherein the volatiles pass oil from the sealing com und or protective coating on the can ends or cone tops while they are being fed upwardly toward the higher temperature chamber portion.

With the above and other objects in view which will more fully appear, the nature of the invention will be more clearly understood by following the spaced units, the screws being mounted on a rotor description, the appended claims, and the several views illustratedin the accompanying drawings.

In thedrawings: Figure 1 is a side elevation illustrating the invention. A v i Figure 2 is an enlarged vertical cross section illustrating the air heating and circulating apparatus; 1

Figure 3 is a plan view. Fig re 4 is a horizontal section takenon the line 4-4 on Figure 1.

Figure 5 is a fragmentary horizontal section taken on the line 5-5 on Figure 1;

Figure 6 is a view diagrammatically illustrating an optional arrangement for effecting heater burner control by temperature conditions in the upperand lower air circulating ducts.

In the example of embodiment of the invention herein illustrated, there is included a base structure A upon which is mounted a rotor B operable within an insulated casing C, said rotor including ,the usual can end or cone top unit elevating and guiding means D to be referred to in greater detail hereinafter. The units to be dried or baked v and lower plates.

are fed into the casing and to the elevating means by any suitable infeeding means E, and drying air, either unheated or having the heat thereof controlled to the desired temperature, is circulated through the casing by circulating means generally designated F. When the air is heated, the circulating means includes heating means generally designated G, and the units are delivered from the casing by any suitable outfeeding means generally. designated H.

The base structure includes a table portion 5 having a recess or opening in which is mounted the lower rotorhead or plate 6. The rotor B, of which the plate '6 comprises a part, is indexed station-by-station by indexing means well known in the art and not illustrated. in detail herein, and this rotor includes a center shaft 1 which carries the plate 6 and extends upwardly therefrom. Sets or parallel pairs of lifter screws 8 are includedin the rotor, they being arranged.

screws, the means for indexing the rotor, and the means H for feeding the units from the rotor, all form no part of the present invention and are stressed in detail in the co-pending application for U. S Letters Patent, Serial No. 439,280, filed by Paul E. Pearson and Ralph M. Mero, on April 16, 1942. v For this reason, further detail description of thestructure and arrangement of these parts is deemed unnecessary herein. The present invention relates to the means for circulating the drying or drying and baking air and distributing or dispersing the same through the spaced and upwardly traveling can end or cone top units, and to the means for controlling the temperature and condition of said air.

The upper end of the shaft 1 is mounted in a bearing 12 formed in a spider l3 provided in a head plate l4 which is secured, as at l5, upon the standards 16 which are in turn secured, as at l1, upon the base structure table 5. A ring 18 surrounds the upper rotor plate 9 and is supported on brackets l9 secured to the standards IS. The head plate i4 is equipped with an air throat 20, and air directe'd downwardly through said throat passes through an air sleeve 2| secured to and depending from said head plate and through openings 22 in the upper rotor head plate 9 into a perforated shell or sleeve 23 which is secured, as at 24, to the under surface of the rotor plat 9 and extends downwardly through approximately two-thirds of the depth of the casing C. The shell or sleeve 23 is closed and secured, as at 25, at its lower end to the center shaft 1 and receives air at its upper end from the outlet 26 of a circulating fan 21 which is mounted on a supporting plate 28 secured, as at 29, on the upper ends of the standards l6. The fan 21 is driven by a motor 30 which is also mounted on the supporting plate 28.

The casing structure C comprises a lower cylindrical section and an upper rectangular section. The lower section includes brackets 3| which are secured to the standards 16 and insulated, curved wall sections 32 so curved that they together form the lower cylindrical section ofthe casing. One of the wall sections 32 is hinged, as at 33, so that it can be swung to an open position to render accessible the interior of the casing and the rotor parts therein. The hinged section is retained in its-normal position by spring keepers 34 with which the free edge of the section engages.

The upper or rectangular section of the casing includes a supporting ring or frame 35 which is secured to the standards l6 below the head plate 14 and to which insulated fiat wall sections 36 are attached. One of the wall sections 36 may be hinged, as at 31, and another includes a hinged portion 38 having a lower edge clearance or opening 39 therein through which can ends may be delivered by the outfeeding means generally designated H.

The lower casing section is equipped with a the casing C in parallel relation thereto on a supporting pedestal 44. The stack 43 includes at its lower end a combustion chamber surrounding shell 45 which, like the upper portion of the stack, is surrounded by an insulating covering or jacket 46. The base 41 of the stack 43, 45 has a Bunsen burner 48 mounted centrally therein so that the flame from the burner extends upwardly into a fire-brick-lined combustion chamber 49 which is supported on said base. The burner is supplied with gas through a supply pipe 50, and air for combustion is supplied through an air inlet 5| provided in the supporting pedestal 44, the amount of air thus introduced being regulatable by a valve 52 mounted in the base and which may be controlled by a knob 53 extended outside the base.

At its upper extremity, the stack is closed by a safety closure or blow-off plate 54 which rests by gravity over the upper open end of the duct and is attached to the duct by a securing chain 55.

The duct 43, 45 is connected at its upper end by a connecting duct 56 with the inlet 51 of the air circulating fan 21 hereinbefore referred to, and the connecting duct 56 is provided with an insulating covering 58. This duct is also equipped with a panel 59 which is removably mounted as at 60. This panel may include a mounting for a suitable temperature control such as the Partlow control well known in the art and diagrammatically illustrated at 6| in Figure 6 of the drawings.

The circulating system also includes a duct 62 which connects the lower part of the casing with a lower portion of the heat stack shell 45, said duct being provided with an insulating cover 63. This duct 62 also includes a panel 64 which is removably mounted as at 65. This slide also may beprovided with a mounting for a suitable temperature control such as the Partlow control which is diagrammatically illustrated at 66 in Figure 6 of the drawings.

It is desirable that an air inlet be provided in the suction side of the air circulating ducting so that a controlled amount of fresh air can beintroduced into the circulation. This may be ac- Y complished by providing an adjustable valve 61 in slide door 40 at the bottom thereof through which the casing, and this duct is equipped with a damper 42 or other suitable control equipment which will enable the controlling of the amount of air permitted to exhaust throu h the duct. 'A heater stack 43 is mounted a distance from the panel 64, or thi inlet may be provided in iany other suitable place in the ducting referred In Figure 6 of the drawings, the control units 61 and 66 hereinabove referred to as mounted on the upper and lower circulating ducts 56 end 62 are diagrammatically shown as connected in series, as at68, with a source of power 69 and a bLu IIBer control unit diagrammatically illustrated a The Partlow control units are well known in the art, and the upper and lower control units 6| and 66 can be set to make and break the control circuit 68 connected with the burner unit 10 according to temperature conditions existing in the upper and lower ducts 56 and 62, and these control units being connected in series, the control circuit 68 will be completed and the burner control 10 actuated to supply heat only when there is a heat demand in both the upper and lower ducts 56 and 62.

In operation, can end or cone top units having protective coatings thereon are fed one-by-one into the casing C between the sets or pairs of elevator screws, and the rotor is indexed so as to serially present the sets of screws at the can end receiving station and to impart rotation to the screws and effect step-by-step elevation by the units in spaced relation on the screws. A full rotation is imparted to each lifter screw during each full turn of the rotor bearing said screws, and at each full rotation of the lifter screws of the screw sets, the units supported by the spiral ribs of the screws will each be lifted one space or pitch distance. In.this manner the can ends or cone tops are lifted in uniformly spaced relation.

While the can ends or' cone tops are being lifted in spaced relation in the manner stated, air is distributed uniformly, outwardly and downwardly through the spaced units in a Sort of countercurrent stream assured by the operation of the circulating fan, a controlled amount of air being exhausted through the exhaust duct ll. The amount of this exhaust can be controlled by adjustment of the damper or similar control valve means 42. The amount of fresh air inducted into the circulation may also be regulated by adjustment of the valve 61.

It is to be understood that the burner can be left out of operation and the apparatus operated on the principle of an air drier alone whenever desired, or the burner can be utilized in conjunction with the various controls hereinbefore described for providing a controlled heat condition in the apparatus in addition to the mere circulation of-air.

The particular arrangement of the air circulating ducting, the perforated shell 23, and the various controls, .serve to provide a chamber portion which is relatively hot at the upper portion of the casing and a chamber portion which is relatively cool at the lower portion of the casing. By this means it is possible to maintain a heat approximating 450 F. near the top of the casing and a temperature of 150 F. near the bottom of the casing. This 'is found to be very advantageous in the drying of compounds or coatings including volatile solvents. The volatiles are removed from a the compounds or coatings in the lower, cooler dried therein, an air inlet Opening centrally and portion of the chamber, and the, upper part of the chamber can act to hard dry or bake the' coatings according to the controlled temperature. It is to be understood, however, that the control units 6| and 66 in the upper and lower ducts 56 and 62 are regulated according to the respective high and relatively low temperatures intendedto prevail in the respective .ducts. The gradual heating of units having sealing compounds thereon, from the relatively low temperature at the bottom to the relatively high temperature at the top, eliminates blistering oi the sealing compound.

By adjustment of the exhaust duct damper 42,

- it is possible to control the amount of air exhausted from the system so as to meet the requirements of the underwriters with relation to safe operation in the drying of solvent type coatings or compounds, and for controlling the volume of air xhausted so as to permit emcient and economical evaporation of water from water base compounds and prevent the condensation of the water vapor in the drier,

It is of course to be understood that the details of structure and arrangement of parts may be I insulated casing generally ,cyli'ndriform in shape and having its axis uprightly disposed, means for moving can ends vertically and in generally parallel spaced relation through said casing to be dried therein, an air inlet opening centrally and downwardly into the casing, an exhaust duct lead- ;ing from the casing near the bottom thereof, an

through said can ends, said sleeve being closed at its lower .end andhaving its lower end spaced above the bottom of the casing about one third the depth of the casing.

2. In apparatus of the character described, an insulated casing generally cylindriform in shape and having its axis uprightly disposed, means for moving can ends vertically and in generally parallel spacedrelationthroughsaid casingto be dried therein, an air inlet opening centrally and downwardly into the casing, an exhaust duct leading from the casing near the bottom thereof, an outlet leading from a lower portion of the casing, ducts connecting the outlet with the inlet, a fan connected in said ducts for forcing a circulation of air therethrough and downwardly through the casing, a perforated air dispersing sleeve supported within the casing in spaced relation to the walls thereof and communicating atits upper end with the inlet so as to receive air therefrom and uniformly distribute it outwardly through said can ends, means for controlling the amount of air releasable out of circulation through said exhaust duct, and means for admitting a controllable amount of fresh air into the air in circulation.

3. In apparatus of the character described, an insulated casing generally cylindriform in shape and having its axis uprightly disposed, means for moving can ends vertically and in generally parallel spaced relation through said casing to be downwardly into the casing, a stack'duct spaced from and disposed in generally parallel relation to said casing, an outlet leading from a lower portion of the casing, an air circulating'fan unit supported atop the casing and having a discharged throat disposed to deliver air into said centrally disposed opening and a horizontally disposed in-' take, a duct connecting the intake with the upper part of the stack and completing an air circulating path including the fan unit, the casing, the stack and the two ducts, a gas burner heating unit disposed in the lower portion of the stack, a combustion chamber forming shell surrounding the burner in spaced relation within the stack opposite the entrance into the stack of the lower duct and extending above said entrance, means for exhausting acontrolled amount of air from the air circulating path, means for introducing a controlled amount of fresh air into said air circulating path, and a perforated air dispersing sleeve supported within the casing in spaced relation to the walls thereof and communicating at its upper end with the inlet so as to receive air therefrom and uniformly distribute it outwardly through said can ends, said sleeve being closed at its lower end and having its lower end spaced above the bottom of the casing aboutone third the depth of the casing.

4 In apparatus of the character described, an insulated casing generally cylindriform in shape and having its axis u rightly disposed, means for moving can ends vertically in close parallel spaced relation and in a multiple of columns with the column axes arranged in equidistantly spaced rela-,

and having its axis uprightly disposed, means for moving can ends vertically in close parallel spaced relation and in a multiple of columns with the column axes arranged in equidistantly spaced relation in a circle concentrically spaced about said casing axis, an air inlet opening centrally and downwardly into the casing within said circle of columns, an exhaust duct leading from the casing near the bottom thereof, an outlet leading from a lower portion of the casing, ducts connecting -the outlet with the inlet, a fan connected in said ducts for forcing a circulation of air therethrough and downwardly through the casing, and, means for controllably introducing make-up air into said circulation.

6. In apparatus of the character described, an insulated casing generally cylindriform in shape and having its axis uprightly disposed, means for moving can ends vertically in close parallel spaced relation in a circle concentrically spaced about column axes arranged in equidistantly spaced relation and in a multiple of columns with the said casing axis, an air inlet opening centrally and downwardly into the casing within said circle of columns, an exhaust duct leading from the cas ing near the bottom thereof, an outlet leading from a lower portion of the casing, ducts connecting the outlet with the inlet, a fan connected in said ducts for forcing a circulation of air therethrough and downwardly through the casing,

means for introducing make-up air into said circulation, and a cylindriform perforated air sleeve 7. In apparatus of the character described, an insulated casing generally cylindriform in shape and having its axis uprightly disposed, means for moving can ends vertically in close parallel spaced relation and in a multiple of columns with the column axes arranged in equidistantly spaced relation in a circle concentrically spaced about said casing axis, an'air inlet opening centrally and downwardly into the casing within said circle of columns, a stack duct spaced from and disposed in generally parallel relation to said casing, an outlet leading from a lower portion of the casing, a duct connecting the outlet with the lower portion of the stack, a duct connecting the inlet with the upper part of the stack and completing an air circulating path including the casing, the stack and the two connecting ducts, anair circulating fan in said air circulating path for providing forced circulation of air therethrough, air heating means in the stack, means for exhausting a controlled amount of air from the air circulating path, and means for introducing a controlled amount of fresh air into said air circulating path.

8. In apparatus of the character described, an insulated casing generally cylindriform in shape and having its axis uprightly disposed, means for moving can ends vertically in close parallel spaced relation and in a multiple of columns with the column axes arranged in equidistantly spaced relation in a circle concentrically spaced about said casing axis, an air inlet opening centrally and downwardly into the casing within said circle of columns, a stack duct spaced from and disposed in generally parallel relation to said casing, an outlet leading from a lower portion of the casing, an air circulating fan unit supported atop the casing and having a discharge throat disposed to deliver air into said centrally disposed opening and a horizontally disposed intake, a duct connecting the intake with the upper part of the stack and completing an air circulating path including the fan unit, the casing, the stack and the two ducts, a gas burner heating unit disposed in the lower portion of the stack, a combustion chamber forming shell surrounding the burner in spaced relation within the stack opposite the entrance into the stack of the lower duct and extending above said entrance, means for exhausting a controlled amount of air from the air circulating path, and means for introducing a controlled amount of fresh air into said air circulating path.

PAUL E. PEARSON. 

